CVE-2026-9277

HIGHPre-NVD 8.18.1
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under NVD CVSS v3. EPSS exploit probability: 0.6%, top 55% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
8.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.1Exploit: NoneExposed: 0

A fix is available — apply it.

shell-quote's quote() function did not validate object-token inputs against the operator model used by parse(). The .op field was backslash-escaped character by character using /(.)/g, which in JavaScript does not match line terminators (\n, \r, U+2028, U+2029). A line terminator in .op therefore passed through unescaped into the output; POSIX shells treat a literal newline as a command separator, so any content after it would execute as a second command. The vulnerable code path is reachable in two ways: (1) direct construction of { op: '...\n...' } from external input, and (2) via parse(cmd, envFn) when envFn returns object tokens whose .op is attacker-influenced. Both are documented API surface. Fixed by replacing the per-character escape with strict shape validation: .op must match the parser's control-operator allowlist; { op: 'glob', pattern } validates pattern and forbids line terminators; { comment } validates comment and forbids line terminators; any other object shape throws TypeError.

CVSS v3
8.1
EG Score
8.1(medium)
EPSS
54.3%
KEV
Not listed

Published

May 22, 2026

Last Modified

July 22, 2026

Advisory Details (3)

Auto-updated Jun 3, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

shell-quote quote() does not escape newlines in object .op values · Advisory · ljharb/shell-quote · GitHub

https://github.com/ljharb/shell-quote/security/advisories/GHSA-w7jw-789q-3m8p
generic🟡 PoC Available

oss-security - CVE-2026-9277: shell-quote before 1.8.4 command injection in quote()

http://www.openwall.com/lists/oss-security/2026/05/23/2
generic

GitHub - ljharb/shell-quote · GitHub

https://github.com/ljharb/shell-quote

Patch Availability(12)

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
shell-quote1.8.4

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 9× in last 7d / 39× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-21 15:25 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-17 18:59 UTCOSV refresh
  9. 2026-07-16 17:03 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 02:00 UTCEPSS rescore
  12. 2026-07-13 22:31 UTCEPSS rescore
  13. 2026-07-13 06:13 UTCEPSS rescore
  14. 2026-07-12 05:46 UTCEPSS rescore
  15. 2026-07-11 08:27 UTCEPSS rescore
  16. 2026-07-09 19:10 UTCEPSS rescore
  17. 2026-07-08 15:16 UTCEPSS rescore
  18. 2026-07-07 13:46 UTCEPSS rescore
  19. 2026-07-06 16:27 UTCEPSS rescore
  20. 2026-07-06 02:23 UTCEPSS rescore
  21. 2026-07-05 02:31 UTCEPSS rescore
  22. 2026-07-04 06:31 UTCEPSS rescore
  23. 2026-07-04 06:31 UTCEPSS rescore
  24. 2026-07-01 15:07 UTCEPSS rescore
  25. 2026-06-30 23:22 UTCEPSS rescore
Show 58 more
  1. 2026-06-29 16:38 UTCVendor advisory
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-28 14:07 UTCEPSS rescore
  4. 2026-06-28 07:49 UTCVendor advisory
  5. 2026-06-28 04:56 UTCEPSS rescore
  6. 2026-06-27 19:32 UTCVendor advisory
  7. 2026-06-27 07:22 UTCVendor advisory
  8. 2026-06-27 03:08 UTCEPSS rescore
  9. 2026-06-26 19:13 UTCVendor advisory
  10. 2026-06-26 03:18 UTCVendor advisory
  11. 2026-06-25 13:57 UTCVendor advisory
  12. 2026-06-25 13:50 UTCEPSS rescore
  13. 2026-06-24 14:05 UTCEPSS rescore
  14. 2026-06-23 21:33 UTCEPSS rescore
  15. 2026-06-22 14:25 UTCEPSS rescore
  16. 2026-06-21 14:56 UTCEPSS rescore
  17. 2026-06-21 01:59 UTCEPSS rescore
  18. 2026-06-19 19:26 UTCEPSS rescore
  19. 2026-06-18 17:52 UTCEPSS rescore
  20. 2026-06-17 23:10 UTCVendor advisory
  21. 2026-06-17 17:53 UTCEPSS rescore
  22. 2026-06-17 10:57 UTCVendor advisory
  23. 2026-06-16 19:24 UTCVendor advisory
  24. 2026-06-16 17:53 UTCEPSS rescore
  25. 2026-06-16 03:04 UTCVendor advisory
  26. 2026-06-15 17:49 UTCEPSS rescore
  27. 2026-06-15 17:49 UTCEPSS rescore
  28. 2026-06-15 14:54 UTCVendor advisory
  29. 2026-06-14 23:18 UTCEPSS rescore
  30. 2026-06-14 22:15 UTCVendor advisory
  31. 2026-06-14 10:05 UTCVendor advisory
  32. 2026-06-13 23:00 UTCEPSS rescore
  33. 2026-06-13 21:53 UTCVendor advisory
  34. 2026-06-13 08:49 UTCVendor advisory
  35. 2026-06-12 23:12 UTCEPSS rescore
  36. 2026-06-12 23:12 UTCEPSS rescore
  37. 2026-06-12 20:38 UTCVendor advisory
  38. 2026-06-12 08:26 UTCVendor advisory
  39. 2026-06-11 20:17 UTCVendor advisory
  40. 2026-06-11 14:00 UTCEPSS rescore
  41. 2026-06-10 22:19 UTCEPSS rescore
  42. 2026-06-10 13:22 UTCEPSS rescore
  43. 2026-06-08 14:17 UTCEPSS rescore
  44. 2026-06-07 15:25 UTCEPSS rescore
  45. 2026-06-06 13:47 UTCEPSS rescore
  46. 2026-06-05 22:47 UTCEPSS rescore
  47. 2026-06-05 06:10 UTCEPSS rescore
  48. 2026-06-04 13:12 UTCEPSS rescore
  49. 2026-06-02 20:13 UTCEPSS rescore
  50. 2026-06-01 13:52 UTCEPSS rescore
  51. 2026-05-31 22:30 UTCEPSS rescore
  52. 2026-05-31 00:16 UTCEPSS rescore
  53. 2026-05-29 13:44 UTCEPSS rescore
  54. 2026-05-28 13:44 UTCEPSS rescore
  55. 2026-05-27 13:40 UTCEPSS rescore
  56. 2026-05-26 13:44 UTCEPSS rescore
  57. 2026-05-26 07:18 UTCEPSS rescore
  58. 2026-05-23 03:58 UTCEG score recompute

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

Frequently asked(5)

What is CVE-2026-9277?
CVE-2026-9277 is a high vulnerability published on May 22, 2026. shell-quote's quote() function did not validate object-token inputs against the operator model used by parse(). The .op field was backslash-escaped character by character using /(.)/g, which in JavaScript does not match line terminators (\n, \r, U+2028, U+2029). A line terminator in .op therefore…
When was CVE-2026-9277 disclosed?
CVE-2026-9277 was first published in the National Vulnerability Database on May 22, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9277 actively exploited?
CVE-2026-9277 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 54.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-9277?
CVE-2026-9277 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-9277?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9277, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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